Picture centering mechanism for motion-picture projection apparatus



Jan. 4, 1949. A. M. a. CHARLIN 2,458,346

PICTURE CENTERING MECHANISM FOR MOTION PICTURE PROJECTION APPARATUS Filed June 6. 1947 Patented Jan. 4, 1949 PICTURE CENTERIN G MECHANISM FOR MOTION-PICTURE PROJECTION APPA- RATUS Andr Marie Bernard Charlin, Montrouge, France Application June 6, 1947, Serial No. 752,992 In France June 22, 1946 3 Claims.

1 In motion picture projection apparatus, it is necessary to provide a device for adjusting the centring in the case in which the film is attached to the claws of the feed drum by means of perforations which do not effect the centring of the pictures in the gate.

The present invention has for its object to provide a centring device which enables this adjustment to be made in a very simple manner.

According to the invention, the Maltese cross shaft is provided, in the portion thereof supporting the drum provided with claws for feeding the film, with two diametrically opposite oblique slots and the feed drum is also provided, in the part thereof fitted over said shaft, with two oblique slots crossing those of the shaft, then a diametrical pin is passed through the four slots, said pin being placed at the intersection of the four slots, being located at the middle of each of said slots in the normal position and being adapted to be moved by a suitable control towards one or other end of said slots in order to impart a rotary motion to the drum relatively to the shaft for adjusting the centring.

According to an embodiment, the pin which is engaged in the four oblique slots also passes through the end of a spindle which is so supported that it can rotate in a screw that can be screwed in either direction in a stationary nut.

Further objects and advantages of my invention will be apparent from the description and claims.

In the drawing, in which an embodiment of my invention is illustrated Fig. l. is a sectional elevation of the mechanism.

Fig. 2 is a plan view of the shaft of the drum, said drum being shown in section.

Fig. 3 is a plan view of the drum.

In these figures, I designates the gate for the film and 2 the feed drum for same, which is provided with the claws 2' The Maltese cross 3 is driven by a finger 4 of the actuating plate which is driven by the worm gearing 5-6. The shaft 1, driven by the Maltese cross 3, has a hollow portion 1' on which is mounted the feed drum 2. The hollow portion 1 is provided, at the portion where the drum 2 is mounted, with two diametrically opposite oblique slots 8 and the drum 2 is also provided, in the tubular portion thereof which is passed over the shaft 1, with two diametrically opposite oblique slots 9 which cross the slots 8 of the shaft 1. A pin I0 is passed through the two slots 9 and through the two slots 8 and also through the end ll of a spindle 12 which is rotatably supported in a sleeve I3 in which it is held by locking balls 20. The sleeve I3 is secured by means of a pin l4 to a screw I5 screwing in a stationary nut IS. A crank I! provided with a handle l8 is fixed by means of a pin I9 on the end of the screw I5. The cage 2|, in which are housed the balls 20, is resiliently held in the sleeve 13 by means of washers 22.

Normally, the pin I0 is located in the middle of the oblique slots 8 and 9, at the intersection of these four slots. If, owing to the perforations of the film having been badly engaged on the feed claws, said film is not centred in the gatewhich the operator can immediately see on the screen-it is only necessary to turn the crank I! by means of the handle l8 in order to move the screw forwards or backwards in the stationary nut l6. Said screw as it moves carries with it the spindle 12 which pushes or pulls, according to the direction, the pin ID in the slots 8 and 9. Owing to the obliqueness of said slots, a relative rotary movement is thus produced between the feed drum 2 for the film and the shaft 'll' driven by the Maltese cross, said relative rotary movement of the drum having the effect of moving the film forwards or backwards a distance of one or more perforations so as to centre said film.

The pin Ill serves for the adjustment, as described, but does not serve to transmit the movement of the Maltese cross to the drum. The drive of the drum is effected by the friction plate 23 which bears against a check of the shaft 'l'l' and against which bears one of the faces of the drum, said drum being pushed against said plate by resilient conical washers 24.

Various modifications may be made in the embodiment illustrated and described without exceeding the scope of the invention. In particular, the arrangement of the Maltese cross shaft may be constructed in any manner and the screw for actuating the spindle [2 which controls the pin l0 may also be constructed in various ways.

Further modifications will be apparent to those skilled in the art and it is desired, therefore, that the invention be limited only by the scope of the appended claims.

1. A picture centring mechanism for motion picture projection apparatus, which comprises a Maltese cross driven in the usual manner, a shaft secured to said cross, said shaft having a hollow portion thereon, a drum provided with claws for feeding the film and mounted on said hollow portion, two diametrically opposite oblique slots in the hollow portion of the shaft, two oblique slots in the drum which cross these of the shaft, a rod arranged in alignment with the first mentioned shaft and engaging with its end in the hollow portion of said shaft, a pin passing through the four slots and said end of the rod, a sleeve supporting said rod, members for locking the rod in the sleeve, a screw secured to said sleeve, a stationary nut co-operating with said screw, an actuating member on the screw a cheek on said hollow portion, a friction plate bearing against said cheek and against one of the faces of said drum, and resilient conical washers pushing said drum against said friction plate.

2. A picture centring mechanism for motion picture projection apparatus, which comprises a Maltese cross driven in the usual manner, a shaft secured to said cross, said shaft having a hollow portion thereon, a drum provided with claws for feeding the film and mounted on said hollow portion, two diametrically opposite oblique slots in the hollow portion of the shaft, two oblique slots in the drum which cross those of the shaft, a rod arranged in alignment with the first mentioned shaft and engaging with its end in the hollow portion of said shaft, a pin passing through the four slots and said end of the rod, a sleeve supporting said rod, a groove in the portion of the rod located in the sleeve, a washer on each side of said groove, balls located in the groove between said washers, a screw having a smooth end engaged in the sleeve in alignment with the rod, a pin securing said end of the said sleeve to the smooth end of said screw, resilient members interposed between the end of the rod and the end of the screw in the sleeve, a nut co-operating with the screw and an actuating member on the screw.

3. A picture centring mechanism for motion picture projection apparatus, which comprises a Maltese cross driven in the usual manner, a shaft secured to said cross, said shaft having a hollow portion thereon, a drum provided with claws for feeding the film and mount-ed on said hollow portion, two diametrically opposite oblique slots in the hollow portion of the shaft, two oblique slots in the drum which cross those of the shaft, a rod arranged in alignment with the first mentioned shaft and engaging with its end in the hollow porion of said shaft, a pin passing through the four slots and said end of the rod, a sleeve supporting said rod, a groove in the portion of the rod located in the sleeve, a washer on each side of said groove, balls located in the groove between said washers, a screw having a smooth end engaged in the sleeve in alignment with the rod, a pin securing said end of the said sleeve to the smooth end of said screw, resilient members between the end of the rod and the end of the screw in the sleeve, a nut co-operating with the screw and an actuating member on the screw, a cheek on the shaft, a friction clutch plat-e pressed against said cheek, resilient members pushing the drum against said clutch plate and driving same.

ANDRE MARIE BERNARD C'HARLIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,989,166 Day Jan. 29, 1935 2,037,454 Boecking Apr. 14:, 1936 FOREIGN PATENTS Number Country Date 332,366 Germany Jan. 31, 1921 23,332 France Nov. 2, 1941 (2nd addition to 476,089) 

